// Copyright 2014 PDFium Authors. All rights reserved. | |
// Use of this source code is governed by a BSD-style license that can be | |
// found in the LICENSE file. | |
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com | |
#ifndef _JBIG2_BIT_STREAM_H_ | |
#define _JBIG2_BIT_STREAM_H_ | |
#include "JBig2_Define.h" | |
class CJBig2_BitStream : public CJBig2_Object | |
{ | |
public: | |
CJBig2_BitStream(FX_BYTE *pBuffer, FX_DWORD dwLength); | |
CJBig2_BitStream(CJBig2_BitStream &bs); | |
~CJBig2_BitStream(); | |
FX_INT32 readNBits(FX_DWORD nBits, FX_DWORD *dwResult); | |
FX_INT32 readNBits(FX_DWORD nBits, FX_INT32 *nResult); | |
FX_INT32 read1Bit(FX_DWORD *dwResult); | |
FX_INT32 read1Bit(FX_BOOL *bResult); | |
FX_INT32 read1Byte(FX_BYTE *cResult); | |
FX_INT32 readInteger(FX_DWORD *dwResult); | |
FX_INT32 readShortInteger(FX_WORD *wResult); | |
void alignByte(); | |
void align4Byte(); | |
FX_BYTE getAt(FX_DWORD dwOffset); | |
FX_BYTE getCurByte(); | |
FX_BYTE getNextByte(); | |
FX_INT32 incByteIdx(); | |
FX_BYTE getCurByte_arith(); | |
FX_BYTE getNextByte_arith(); | |
FX_DWORD getOffset(); | |
void setOffset(FX_DWORD dwOffset); | |
FX_DWORD getBitPos(); | |
void setBitPos(FX_DWORD dwBitPos); | |
FX_BYTE *getBuf(); | |
FX_DWORD getLength() | |
{ | |
return m_dwLength; | |
} | |
FX_BYTE *getPointer(); | |
void offset(FX_DWORD dwOffset); | |
FX_DWORD getByteLeft(); | |
private: | |
FX_BYTE *m_pBuf; | |
FX_DWORD m_dwLength; | |
FX_DWORD m_dwByteIdx; | |
FX_DWORD m_dwBitIdx; | |
}; | |
inline CJBig2_BitStream::CJBig2_BitStream(FX_BYTE *pBuffer, FX_DWORD dwLength) | |
{ | |
m_pBuf = pBuffer; | |
m_dwLength = dwLength; | |
m_dwByteIdx = 0; | |
m_dwBitIdx = 0; | |
if (m_dwLength > 256 * 1024 * 1024) { | |
m_dwLength = 0; | |
m_pBuf = NULL; | |
} | |
} | |
inline CJBig2_BitStream::CJBig2_BitStream(CJBig2_BitStream &bs) | |
{ | |
m_pBuf = bs.m_pBuf; | |
m_dwLength = bs.m_dwLength; | |
m_dwByteIdx = bs.m_dwByteIdx; | |
m_dwBitIdx = bs.m_dwBitIdx; | |
} | |
inline CJBig2_BitStream::~CJBig2_BitStream() | |
{ | |
} | |
inline FX_INT32 CJBig2_BitStream::readNBits(FX_DWORD dwBits, FX_DWORD *dwResult) | |
{ | |
FX_DWORD dwTemp = (m_dwByteIdx << 3) + m_dwBitIdx; | |
if(dwTemp <= (m_dwLength << 3)) { | |
*dwResult = 0; | |
if(dwTemp + dwBits <= (m_dwLength << 3)) { | |
dwTemp = dwBits; | |
} else { | |
dwTemp = (m_dwLength << 3) - dwTemp; | |
} | |
while(dwTemp > 0) { | |
*dwResult = (*dwResult << 1) | ((m_pBuf[m_dwByteIdx] >> (7 - m_dwBitIdx)) & 0x01); | |
if(m_dwBitIdx == 7) { | |
m_dwByteIdx ++; | |
m_dwBitIdx = 0; | |
} else { | |
m_dwBitIdx ++; | |
} | |
dwTemp --; | |
} | |
return 0; | |
} else { | |
return -1; | |
} | |
} | |
inline FX_INT32 CJBig2_BitStream::readNBits(FX_DWORD dwBits, FX_INT32 *nResult) | |
{ | |
FX_DWORD dwTemp = (m_dwByteIdx << 3) + m_dwBitIdx; | |
if(dwTemp <= (m_dwLength << 3)) { | |
*nResult = 0; | |
if(dwTemp + dwBits <= (m_dwLength << 3)) { | |
dwTemp = dwBits; | |
} else { | |
dwTemp = (m_dwLength << 3) - dwTemp; | |
} | |
while(dwTemp > 0) { | |
*nResult = (*nResult << 1) | ((m_pBuf[m_dwByteIdx] >> (7 - m_dwBitIdx)) & 0x01); | |
if(m_dwBitIdx == 7) { | |
m_dwByteIdx ++; | |
m_dwBitIdx = 0; | |
} else { | |
m_dwBitIdx ++; | |
} | |
dwTemp --; | |
} | |
return 0; | |
} else { | |
return -1; | |
} | |
} | |
inline FX_INT32 CJBig2_BitStream::read1Bit(FX_DWORD *dwResult) | |
{ | |
if(m_dwByteIdx < m_dwLength) { | |
*dwResult = (m_pBuf[m_dwByteIdx] >> (7 - m_dwBitIdx)) & 0x01; | |
if(m_dwBitIdx == 7) { | |
m_dwByteIdx ++; | |
m_dwBitIdx = 0; | |
} else { | |
m_dwBitIdx ++; | |
} | |
return 0; | |
} else { | |
return -1; | |
} | |
} | |
inline FX_INT32 CJBig2_BitStream::read1Bit(FX_BOOL *bResult) | |
{ | |
if(m_dwByteIdx < m_dwLength) { | |
*bResult = (m_pBuf[m_dwByteIdx] >> (7 - m_dwBitIdx)) & 0x01; | |
if(m_dwBitIdx == 7) { | |
m_dwByteIdx ++; | |
m_dwBitIdx = 0; | |
} else { | |
m_dwBitIdx ++; | |
} | |
return 0; | |
} else { | |
return -1; | |
} | |
} | |
inline FX_INT32 CJBig2_BitStream::read1Byte(FX_BYTE *cResult) | |
{ | |
if(m_dwByteIdx < m_dwLength) { | |
*cResult = m_pBuf[m_dwByteIdx]; | |
m_dwByteIdx ++; | |
return 0; | |
} else { | |
return -1; | |
} | |
} | |
inline FX_INT32 CJBig2_BitStream::readInteger(FX_DWORD *dwResult) | |
{ | |
if(m_dwByteIdx + 3 < m_dwLength) { | |
*dwResult = (m_pBuf[m_dwByteIdx] << 24) | (m_pBuf[m_dwByteIdx + 1] << 16) | |
| (m_pBuf[m_dwByteIdx + 2] << 8) | m_pBuf[m_dwByteIdx + 3]; | |
m_dwByteIdx += 4; | |
return 0; | |
} else { | |
return -1; | |
} | |
} | |
inline FX_INT32 CJBig2_BitStream::readShortInteger(FX_WORD *dwResult) | |
{ | |
if(m_dwByteIdx + 1 < m_dwLength) { | |
*dwResult = (m_pBuf[m_dwByteIdx] << 8) | m_pBuf[m_dwByteIdx + 1]; | |
m_dwByteIdx += 2; | |
return 0; | |
} else { | |
return -1; | |
} | |
} | |
inline void CJBig2_BitStream::alignByte() | |
{ | |
if(m_dwBitIdx != 0) { | |
m_dwByteIdx ++; | |
m_dwBitIdx = 0; | |
} | |
} | |
inline void CJBig2_BitStream::align4Byte() | |
{ | |
if(m_dwBitIdx != 0) { | |
m_dwByteIdx ++; | |
m_dwBitIdx = 0; | |
} | |
m_dwByteIdx = (m_dwByteIdx + 3) & -4; | |
} | |
inline FX_BYTE CJBig2_BitStream::getAt(FX_DWORD dwOffset) | |
{ | |
if(dwOffset < m_dwLength) { | |
return m_pBuf[dwOffset]; | |
} else { | |
return 0; | |
} | |
} | |
inline FX_BYTE CJBig2_BitStream::getCurByte() | |
{ | |
if(m_dwByteIdx < m_dwLength) { | |
return m_pBuf[m_dwByteIdx]; | |
} else { | |
return 0; | |
} | |
} | |
inline FX_BYTE CJBig2_BitStream::getNextByte() | |
{ | |
if(m_dwByteIdx + 1 < m_dwLength) { | |
return m_pBuf[m_dwByteIdx + 1]; | |
} else { | |
return 0; | |
} | |
} | |
inline FX_INT32 CJBig2_BitStream::incByteIdx() | |
{ | |
if(m_dwByteIdx < m_dwLength) { | |
m_dwByteIdx ++; | |
return 0; | |
} else { | |
return -1; | |
} | |
} | |
inline FX_BYTE CJBig2_BitStream::getCurByte_arith() | |
{ | |
if(m_dwByteIdx < m_dwLength) { | |
return m_pBuf[m_dwByteIdx]; | |
} else { | |
return 0xff; | |
} | |
} | |
inline FX_BYTE CJBig2_BitStream::getNextByte_arith() | |
{ | |
if(m_dwByteIdx + 1 < m_dwLength) { | |
return m_pBuf[m_dwByteIdx + 1]; | |
} else { | |
return 0xff; | |
} | |
} | |
inline FX_DWORD CJBig2_BitStream::getOffset() | |
{ | |
return m_dwByteIdx; | |
} | |
inline void CJBig2_BitStream::setOffset(FX_DWORD dwOffset) | |
{ | |
if (dwOffset > m_dwLength) { | |
dwOffset = m_dwLength; | |
} | |
m_dwByteIdx = dwOffset; | |
} | |
inline FX_DWORD CJBig2_BitStream::getBitPos() | |
{ | |
return (m_dwByteIdx << 3) + m_dwBitIdx; | |
} | |
inline void CJBig2_BitStream::setBitPos(FX_DWORD dwBitPos) | |
{ | |
m_dwByteIdx = dwBitPos >> 3; | |
m_dwBitIdx = dwBitPos & 7; | |
} | |
inline FX_BYTE *CJBig2_BitStream::getBuf() | |
{ | |
return m_pBuf; | |
} | |
inline FX_BYTE *CJBig2_BitStream::getPointer() | |
{ | |
return m_pBuf + m_dwByteIdx; | |
} | |
inline void CJBig2_BitStream::offset(FX_DWORD dwOffset) | |
{ | |
m_dwByteIdx += dwOffset; | |
} | |
inline FX_DWORD CJBig2_BitStream::getByteLeft() | |
{ | |
return m_dwLength - m_dwByteIdx; | |
} | |
#endif |